Why is my run configuration disabled in Android Studio?

Question

My app is called QEventShare. There are no compilation errors. Just 5 minutes ago, I would have been able to run the app, but now for some reason, I cannot.

If you look by where the Run Button is, you will notice that it is unclickable. You will also notice a '?' and X by my app name (left of the run button).

Why is this happening and how can I fix it?

I've exited and restarted Android Studio twice to no avail.

Answer 1

I know it is too late, but it could be useful for somebody. As @Gabriele said, go to the combo just to the left of the run button, open it and select the main module of your project. It should be enough to enable run button again.

Cheers.

Answer 2

我的解决方案是重启项目。